What defines a clerestory in architecture?

A clerestory in architecture is defined as a portion of an interior that rises above rooftops, specifically designed to allow natural light to enter a building. This architectural feature typically consists of a row of windows placed high on the wall, above the line of the roof. Clerestories are often used in large buildings, such as churches, cathedrals, and auditoriums, to illuminate the space while maintaining privacy and reducing glare from direct sunlight. This positioning not only enhances the aesthetic appeal of the structure but also ensures effective light penetration without compromising the integrity of the building's design or its structural elements.

The other options do not accurately capture the essence of a clerestory. An ornamented window or decorative door style focuses more on aesthetics without considering functionality, while a bay window refers specifically to a protruding window structure that doesn’t serve the unique lighting purpose of a clerestory.